Glossary
SITRANS F C MC2
Operating Instructions, 10/2009, A5E02154544-02
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PROFIBUS
PROFIBUS (Process Field Bus) is a vendor-independent, open bus system standardized in
the German DIN 19 245. It is a standard for field bus communication in automation
technology and should not be confused with the PROFINET standard for industrial Ethernet.
PROFIBUS-PA (Process Automation) is one of three PROFIBUS variants that are
compatible with each other. PROFIBUS-DP (Decentralized Periphery)
SENSORPROM
All sensor related settings/data saved on an EPROM. SENSORPROM technology
automatically configures the transmitter at start up providing calibration data, pipe size,
sensor type, and output settings. The SENSORPROM automatically stores values or
settings changed by users, and automatically re-programs any new transmitter without loss
of accuracy.
Turndown ratio
'Turndown ratio' is a flow measurement term indicating the range a specific flow meter, or
meter type, is able to measure with acceptable accuracy. It is also known as rangeability. If a
gas flow to be measured is expected to vary between 100,000 m³ per day and 1,000,000 m³
per day, the specific application has a turndown ratio of at 10:1. Therefore the meter requires
a turndown ratio of at least 10:1.
USM
USM II is a Communication Platform. The Siemens USM II concept enables fitting of add-on
bus modules without loss of functionality:
1.
All modules can be fitted as true "plug & play"
2.
Module and transmitter are automatically configured through the SENSORPROM